From 736a8a8ac7abfeab5edb8dfd73ecf0b2c0282e61 Mon Sep 17 00:00:00 2001 From: Paul Sokolovsky Date: Sun, 12 Mar 2017 22:28:45 +0300 Subject: [PATCH] zephyr: Make sure that generated prj.conf is updated only on content changes. This is a typical problem with make: we want to trigger rebuilds only if file actually changed, not if its timestamp changed. In this case, it's aggravated by the fact that prj.conf depends on the value of BOARD variable, so we need to do some tricks anyway. We still don't try to detect if just BOARD changed, just try to generate new prj.conf.tmp every time (quick), but do actual replacement of prj.conf only if its content changed. --- zephyr/Makefile | 3 +-- zephyr/makeprj.py | 29 +++++++++++++++++++++++++++++ 2 files changed, 30 insertions(+), 2 deletions(-) create mode 100644 zephyr/makeprj.py diff --git a/zephyr/Makefile b/zephyr/Makefile index d020ab5ce0..7d4d6674ef 100644 --- a/zephyr/Makefile +++ b/zephyr/Makefile @@ -102,5 +102,4 @@ z_clean: .PHONY: prj.conf prj.conf: prj_base.conf - cat $< >$@ - if [ -f prj_$(BOARD).conf ]; then cat prj_$(BOARD).conf >>$@; fi + $(PYTHON) makeprj.py prj_base.conf prj_$(BOARD).conf $@ diff --git a/zephyr/makeprj.py b/zephyr/makeprj.py new file mode 100644 index 0000000000..239c877cd6 --- /dev/null +++ b/zephyr/makeprj.py @@ -0,0 +1,29 @@ +#!/usr/bin/env python3 +import sys +import os +import hashlib + + +def hash_file(fname): + if not os.path.exists(fname): + return b"" + hasher = hashlib.md5() + with open(fname, "rb") as f: + hasher.update(f.read()) + return hasher.digest() + + +old_digest = hash_file(sys.argv[3]) + +with open(sys.argv[3] + ".tmp", "wb") as f: + f.write(open(sys.argv[1], "rb").read()) + if os.path.exists(sys.argv[2]): + f.write(open(sys.argv[2], "rb").read()) + +new_digest = hash_file(sys.argv[3] + ".tmp") + +if new_digest != old_digest: + print("Replacing") + os.rename(sys.argv[3] + ".tmp", sys.argv[3]) +else: + os.remove(sys.argv[3] + ".tmp")